1. Field of the Invention
The present invention relates to equipment for transporting and positioning tote boxes and wire or steel containers. More specifically, the invention is directed to an improved box tilter for easy access to the contents of such containers.
2. Description of the Related Art
Bin containers of the tote-box and wire- or steel-wall type are used very commonly in manufacturing and warehousing, where prompt and safe access to the contents of a bin is critical for an efficient work environment. For productivity, it is important that workers have a clear view of the items stored in a container, so that they may be able to selectively reach the desired item directly and quickly. For safety, it is essential that workers be able to reach a desired item in the container without bending or stretching beyond normal posture.
With these considerations in mind, many devices have been developed for receiving, storing, transporting and tilting box containers. Typically, these devices consist of a movable support chassis with two vertical masts and a box frame pivotally mounted to the top of the masts. The box frame can assume various tilted positions with respect to the masts, thereby allowing easy access to its contents by a user standing on the other side of the masts. For example, Canadian Patent No. 1,254,861 (1989) describes a tote box tilter having approximately ground-level, horizontal forks mounted on a movable chassis and adapted for supporting a container. The forks are integral with horizontal radial arms projecting forward and pivotally coupled to the top portion of vertical masts integral with the chassis. A hydraulic cylinder is connected in extensible pushing relation between the chassis and the radial arms, such that the radial arms and the forks are pushed upwards as the cylinder is extended. Thus, a container initially placed on the forks is raised and tilted by the action of the cylinder and, when the radial arms and forks reach a substantially vertical position, the container is completely tilted by 90 degrees, thereby allowing a user to reach its bottom without bending forward.
Similar box-tilter equipment is described in Japanese Patents No. 1-38154, No. 59-9731, No. 61-7198, No. 61-169499, No. 61-185792 and No. 62-68999. All of these devices utilize radial-arm means to lift and tilt a container placed on forks or equivalent means attached to the arms. One side of the radial-arm means is hinged to a chassis' vertical masts and the other side is rigidly connected to the forks. In all devices, the actuating force necessary to lift and tilt the forks and the container is provided by hydraulic means connected in extensible pushing relation between the chassis and the radial-arm means, the latter coupling being at a point between the connections with the masts and the forks. Thus, inasmuch as the radial-arm means constitutes the lever arm for pivoting the forks of the device, it must be sufficiently long to permit the use of a reasonably sized and affordable hydraulic cylinder. As well understood by those skilled in the art, a short radial arm would require a correspondingly more powerful hydraulic system and might increase the cost of the device beyond commercial viability. Therefore, radial arms about 30 to 40 centimeter long are typically used.
Inherent in this configuration is the fact that the length of the radial arm necessarily increases the distance of the lifting forks (and therefore also of the container supported by them) from the hinge point on the chassis, which makes it harder for a user to reach the container before it is completely lifted and tilted. In addition, the length of the radial arm increases the height of the container in its lifted position, thereby also limiting its accessibility. If the radial arm is too short, a prohibitively powerful cylinder may be required; if the radial arm is too long, the resulting position of the container may be offset too much for comfortable access by a user. Therefore, there remains a need for an improved box tilter that is designed to overcome these shortcomings. This invention is directed at providing such an improvement.